Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.31.1 (micrococcal nuclease)
 2,818 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biofilm formation transforms infections from acute to chronic, increasing patient mortality and significantly increasing healthcare costs. We are studying the prevalence of some virulence genes among methicillin resistant Staphylococcus aureus (MRSA) isolates relative to biofilm formation and the potential of photoactivated hypericin to treat these infections. Isolates were collected from three Egyptian governorates over seven months in 2011, 100 isolates were identified as MRSA. Biofilm formation was established using crystal violet staining and 2,3,5-triphenyl tetrazolium chloride reduction. Twenty two percent of the isolates formed biofilms, of which 68.2% were moderate to strong. The virulence genes were detected using polymerase chain reaction. spaX (x-region of protein A) was most prevalent. All biofilm-formers lacked cap5 (capsular polysaccharide 5), the other genes were: nuc (thermonuclease) > clfA (clumping factor) > spaIgG (IgG binding site of protein A), fnbA (fibronectin protein A), cap8 (capsular polysaccharide 8), agr (accessory-gene-regulator locus) > fnbB (fibronectin protein B). agr-locus was only found in 22.22% of moderate biofilm-formers, the remaining genes were almost equally prevalent among biofilm-formers and negative controls. Photoactivated hypericin efficiently inhibited 92.2-99.9% of biofilm viability, irrespective of the number of virulence genes. To conclude, biofilm formation, and treatment might be affected by a myriad of virulence factors rather than a single gene, however, photoactivated hypericin remains a potential antibiofilm approach.
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PMID:The degree of virulence does not necessarily affect MRSA biofilm strength and response to photodynamic therapy. 2661 67

Aeromonas veronii is a pathogenic gram-negative bacterium, which infects a variety of animals and results in mass mortality. The stalled-ribosome rescues are reported to ensure viability and virulence under stress conditions, of which primarily include trans-translation and alternative ribosome-rescue factor A (ArfA) in A. veronii. For identification of specific peptides that interact and inhibit the stalled-ribosome rescues, peptide aptamer library (pTRG-SN-peptides) was constructed using pTRG as vector and Staphylococcus aureus nuclease (SN) as scaffold protein, in which 16 random amino acids were introduced to form an exposed surface loop. In the meantime both Small Protein B (SmpB) which acts as one of the key components in trans-translation, and ArfA were inserted to pBT to constitute pBT-SmpB and pBT-ArfA, respectively. The peptide aptamer PA-2 was selected from pTRG-SN-peptides by bacterial two-hybrid system (B2H) employing pBT-SmpB or pBT-ArfA as baits. The conserved sites G133K134 and D138K139R140 of C-terminal SmpB were identified by interacting with N-terminal SN, and concurrently the residue K62 of ArfA was recognized by interacting with the surface loop of the specific peptide aptamer PA-2. The expression plasmids pN-SN or pN-PA-2, which combined the duplication origin of pRE112 with the neokanamycin promoter expressing SN or PA-2, were created and transformed into A. veronii C4, separately. The engineered A. veronii C4 which endowing SN or PA-2 expression impaired growth capabilities under stress conditions including temperatures, sucrose, glucose, potassium chloride (KCl) and antibiotics, and the stress-related genes rpoS and nhaP were down-regulated significantly by Quantitative Real-time PCR (qRT-PCR) when treating in 2.0% KCl. Thus, the engineered A. veronii C4 conferring PA-2 expression might be potentially attenuated vaccine, and also the peptide aptamer PA-2 could develop as anti-microbial drugs targeted to the ribosome rescued factors in A. veronii.
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PMID:Genetic Selection of Peptide Aptamers That Interact and Inhibit Both Small Protein B and Alternative Ribosome-Rescue Factor A of Aeromonas veronii C4. 2758 15